1. Field of the Invention
This invention relates to a drive device, especially for moving the sliding roof of a motor vehicle, which includes an electric motor comprising an armature, a pole shaft and a brush system, gearing driven by the electric motor, and a circuit arrangement for triggering the electric motor, wherein the electric motor is accommodated in a motor housing and the gearing and at least part of the circuit arrangement is accommodated in a gear housing connected to the motor housing.
2. Description of Related Art
One conventional drive device is disclosed in German Published Application No. 100 06 320. In this drive device, the gearing is accommodated in a gear housing which has a gear housing area and a circuit housing area. In one side wall of the circuit housing area there is an opening through which the pole shaft of the electric motor is inserted when the drive device is mounted. The brush system is housed in a brush bridge which is made as a peripheral plastic ring, which on its top has contact-making elements made as press-in contacts in order for the brush system to make contact with the circuit arrangement.
Another similar drive device is also disclosed in German Published Application No. 198 05 185 and corresponding U.S. Pat. No. 6,201,326. In this drive device, the brush system is mounted on a brush-holder support, on which, in addition to brush cartridges, there are also interference suppression coils.
Furthermore, German Published Application No. 100 18 230 discloses a similar drive device in which the brush system has a brush holder-support for holding the brushes and contact-making for the electrical contact with the motor electronics. The brush holder-support is a part which surrounds the pole shaft and which is located within the motor housing.
The disadvantage of the aforementioned drive devices is that the brush system must have its own holding devices which on the one hand mean additional parts and thus costs, and on the other also occupy a relatively large amount of space.
Finally, German Published Application No. 42 33 156 discloses a similar drive device in which, to acquire the rpm and direction of rotation of the electric motor near the pole shaft, there are Hall sensors which are located on a board aligned such that the pole shaft runs perpendicular to the board. In this drive device, the brush system is located on the side of the board facing away from the Hall sensors. The disadvantage in this approach is that, for exact positioning of the individual components, narrow tolerances must be maintained since the placement of the Hall sensors relative to the board, the placement of the brush system on the board and the placement of the board within the gear housing mutually influence one another.